Precedence of pattern operators

The order of precedence for pattern matching is as follows:

{}
:
whitespace . ..
?
|

The alternative operator has the lowest precedence. For example, suppose there are four patterns: A, B, C, and D.
```
A B|C D
```
is equivalent to
```
{A B}|{C D}
```
The example matches an input of A followed by B, or it matches an input of C followed by D.

Grouping patterns by using the braces has the highest level of precedence. For the patterns A, B, C, and D:
```
{A|B} C D
```
is not equivalent to
```
A|B C D
```